Instrument panel assemblies of motor vehicles typically include a plurality of ducts or conduits that are coupled together to deliver force air to various vents located along the instrument panel assembly and/or other parts of the vehicle. Gaskets are typically used for sealing and preventing air leaks at the interface between adjacent conduits. It remains desirable to provide an instrument panel assembly with structure that prevents deformation of the gasket during assembly of the instrument panel assembly, which can potentially block or impede the flow of air through the conduits.